Do you believe in evolution?
The proper Christian answer to that question depends on the meaning of the term.
In their 2003 essay “The Meanings of Evolution,” Stephen C. Meyer and Michael Newton Keas explain the term is actually used in six distinct ways:
- Evolution as change over time
- Evolution as gene frequency change
- Evolution as limited common descent
- Evolution as a mechanism that produces limited change or descent with modification
- Evolution as universal common descent
- Evolution as the “blind watchmaker” thesis
“Mere evolution” (that is, evolution meanings 1–4), they argue, is “one of the strongest and most useful scientific theories we have,” to use language from the National Academy of Sciences. Mere evolution encompasses a vast number of specific cosmological, geological, and biological theories that “incorporate a large body of scientific facts, laws, tested hypotheses, and logical inferences.”
On the other hand, they argue, “a significant minority of scientists dissent on evidential grounds from the theory of universal common descent (evolution #5), and an even greater group dissents from the blind watchmaker hypothesis (evolution #6).”
Here are their explanations for each definition:
1. Evolution as Change Over Time
Nature has a history; it is not static.
Natural sciences deal with evolution in its first sense—change over time in the natural world—when they seek to reconstruct series of past events to tell the story of nature’s history.
- Astronomers study the life cycles of stars;
- geologists ponder the changes in the earth’s surface;
- paleontologists note changes in the types of life that have existed over time, as represented in the sedimentary rock record (fossil succession);
- biologists note ecological succession within recorded human history, which may have, for example, transformed a barren island into a mature forested island community.
Although the last example has little to do with neoDarwinian evolutionary theory, it still fits within the first general sense of evolution as natural historical progression or sequence of events.
2. Evolution as Gene Frequency Change
Population geneticists study changes in the frequencies of alleles in gene pools.
This very specific sense of evolution, though not without theoretical significance, is closely tied to a large collection of precise observations. The melanism studies of peppered moths, though currently contested, are among the most celebrated examples of such studies in microevolution. For the geneticist, gene frequency change is “evolution in action.”
3. Evolution as Limited Common Descent
Virtually all scientists (even many creationists) would agree that Darwin’s dozen or more famed Galapagos Island finch species are probably descended from a single continental South American finch species. Although such “evolution” did not occur during the brief time scale of the lives of scientists since Darwin (as in the case of the peppered moth), the pattern of biogeographical distribution of these birds strongly suggests to most scientists that all of these birds share a common ancestor.
Evolution defined as “limited common descent” designates the scientifically uncontroversial idea that many different varieties of similar organisms within different species, genera, or even families are related by common ancestry.
Note that it is possible for some scientists to accept evolution when defined in this sense without necessarily accepting evolution defined as universal common descent— that is, the idea that all organisms are related by common ancestry.
4. Evolution as a Mechanism that Produces Limited Change or Descent with Modification
The term evolution also refers to the mechanism that produces the morphological change implied by limited common descent or descent with modification through successive generations. Evolution in this sense refers chiefly to the mechanism of natural selection acting on random genetic variation or mutations. This sense of the term refers to the idea that the variation/selection mechanism can generate at least limited biological or morphological change within a population.
Nearly all biologists accept the efficacy of natural selection (and associated phenomena, such as the founder effect and genetic drift) as a mechanism of speciation. Even so, many scientists now question whether such mechanisms can produce the amount of change required to account for the completely novel organs or body plans that emerge in the fossil record.
Thus, almost all biologists would accept that the variation/selection mechanism can explain relatively minor variations among groups of organisms (evolution meaning #4), even if some of those biologists question the sufficiency of the mechanism (evolution meaning #6) as an explanation for the origin of the major morphological innovations in the history of life.
5. Evolution as Universal Common Descent
Many biologists commonly use the term evolution to refer to the idea that all organisms are related by common ancestry from a single living organism.
Darwin represented the theory of universal common descent or universal “descent with modification” with a “branching tree” diagram, which showed all present life forms as having emerged gradually over time from one or very few original common ancestors. Darwin’s theory of biological history is often referred to as a monophyletic view because it portrays all organisms as ultimately related as a single family.
6. Evolution as the “Blind Watchmaker” Thesis
The “blind watchmaker” thesis, to appropriate Richard Dawkins’s clever term, stands for the Darwinian idea that all new living forms arose as the product of unguided, purposeless, material mechanisms, chiefly natural selection acting on random variation or mutation. Evolution in this sense implies that the Darwinian mechanism of natural selection acting on random variations (and other equally naturalistic processes) completely suffices to explain the origin of novel biological forms and the appearance of design in complex organisms.
Although Darwinists and neo-Darwinists admit that living organisms appear designed for a purpose, they insist that such “design” is only apparent, not real, precisely because they also affirm the complete sufficiency of unintelligent natural mechanisms (that can mimic the activity of a designing intelligence) of morphogenesis. In Darwinism, the variation/selection mechanism functions as a kind of “designer substitute.”
As Dawkins summarizes the blind watchmaker thesis:
Natural selection, the blind, unconscious, automatic process which Darwin discovered and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind’s eye.
The Discovery Institute summarizes five areas of science that pose serious problems for the neo-Darwinian model of chemical and biological evolution:
- Genetics: Mutations cause harm and do not build complexity.
- Biochemistry: Unguided and random processes cannot produce cellular complexity.
- Paleontology: The fossil record lacks intermediate fossils.
- Taxonomy: Biologists have failed to construct Darwin’s “Tree of Life.”
- Chemistry: The chemical origin of life remains an unsolved mystery.
Mutations cause harm and do not build complexity.
Darwinian evolution relies on random mutations that are selected by a blind, unguided process of natural selection that has no goals.
Such a random and undirected process tends to harm organisms and does not improve them or build complexity.
As National Academy of Sciences biologist Lynn Margulis has said,
new mutations don’t create new species; they create offspring that are impaired.
Similarly, past president of the French Academy of Sciences, Pierre-Paul Grasse, contended that
“mutations have a very limited ‘constructive capacity’” because “no matter how numerous they may be, mutations do not produce any kind of evolution.”
Unguided and random processes cannot produce cellular complexity.
Our cells contain incredible complexity, like miniature factories using machine technology but dwarfing the complexity and efficiency of anything produced by humans.
Cells use miniature circuits, motors, feedback loops, encoded language, and even error-checking machinery to decode and repair our DNA.
Darwinian evolution struggles to build this type of integrated complexity.
As biochemist Franklin Harold admits:
there are presently no detailed Darwinian accounts of the evolution of any biochemical or cellular system, only a variety of wishful speculations.
The fossil record lacks intermediate fossils.
The fossil record’s overall pattern is one of abrupt explosions of new biological forms, and possible candidates for evolutionary transitions are the exception, not the rule.
This has been recognized by many paleontologists such as Ernst Mayr who explained in 2000 that
new species usually appear in the fossil record suddenly, not connected with their ancestors by a series of intermediates.
Similarly, a zoology textbook observed that
Many species remain virtually unchanged for millions of years, then suddenly disappear to be replaced by a quite different, but related, form. Moreover, most major groups of animals appear abruptly in the fossil record, fully formed, and with no fossils yet discovered that form a transition from their parent group.
Biologists have failed to construct Darwin’s “Tree of Life.”
Biologists hoped that DNA evidence would reveal a grand tree of life where all organisms are clearly related.
Trees describing the alleged ancestral relationships between organisms based upon one gene or biological characteristic very commonly conflict with trees based upon a different gene or characteristic.
As the journal New Scientist put it,
different genes told contradictory evolutionary stories.
The eminent microbiologist Carl Woese explained that such “phylogenetic” conflicts
can be seen everywhere in the universal tree, form its root to the major branchings within and among the various taxa to the makeup of the primary groupings themselves.
This implies a breakdown in common descent, the hypothesis that all organisms share a common ancestor.
The chemical origin of life remains an unsolved mystery.
The mystery of the origin of life is unsolved and all existing theories of chemical evolution face major problems.
Basic deficiencies in chemical evolution include a lack of explanation for how a primordial soup could arise on the early earth’s hostile environment, or how the information required for life could be generated by blind chemical reactions.
As evolutionary biologist Massimo Pigliucci has admitted,
we really don’t have a clue how life originated on Earth by natural means.